In this section, we introduce how to find unionable tables based on contextualized column embeddings.
We first the table unionability scores and introduce the overall workflow of online query processing in Section REF .
Then we discuss the design choices for reducing the number of candidates using vector indices
and deducing bounds for more efficient verification in Sections REF  and REF , respectively.
Note that the online processing techniques explored here are not limited to any specific column encoders, they are also applicable to other dense-vector column representation methods [1]}, [2]}.
